Data.Undefined.NoProblem

newtype Req a

Denotes a required record field, the opposite of Opt. Note that using this type is only required for polymorphic fields, due to complicated type system reasons. Fields that have concrete types are not required to use Req. For example:

type Args a =
  { polymorphicField :: Req a  -- `Req` is needed here
  , optionalField :: Opt a
  , concreteTypedField :: Int  -- no need for `Req` here
  }

Constructors

• Req a

Instances

• Newtype (Req a) _
• (Show a) => Show (Req a)

data Opt t0

Denotes an optional value, typically a record field, allowing the consumer to omit such field when passing the parameter, but still allowing the receiving function to work with the field.

Instances

• (Eq a) => Eq (Opt a)
• (Eq a) => Eq1 Opt
• (Ord a) => Ord (Opt a)
• (Show a) => Show (Opt a)

undefined :: forall a. Opt a

opt :: forall a. a -> Opt a

fromOpt :: forall a. a -> Opt a -> a

Let's be consistent with fromMaybe args order here

fromOptFlipped :: forall a. Opt a -> a -> a

Operator alias for Data.Undefined.NoProblem.fromOptFlipped (left-associative / precedence 9)

toMaybe :: forall a. Opt a -> Maybe a

fromMaybe :: forall a. Maybe a -> Opt a

isUndefined :: forall a. Opt a -> Boolean

unsafeUnwrap :: forall a. Opt a -> a

pseudoBind :: forall a b. Opt a -> (a -> Opt b) -> Opt b

This is not dedicated for providing bind. We are not able to have Monad here.

It is only to provide nice operator: (coerce {}) ? .a ? .b ? _.c.d ! "default"

Operator alias for Data.Undefined.NoProblem.pseudoBind (left-associative / precedence 9)

pseudoMap :: forall a b. (a -> b) -> Opt a -> Opt b

Operator alias for Prim.TypeError.Beside (right-associative / precedence 2)

Ripped from typelevel-eval

Operator alias for Prim.TypeError.Above (right-associative / precedence 1)

data SList

Ripped from record-extra

data SCons :: Symbol -> SList -> SListdata SCons t0 t1

Instances

• RenderPath (SCons n SNil) (QuoteLabel n)
• (RenderPath tail p) => RenderPath (SCons segment tail) (Beside p (Beside (Text ".") (QuoteLabel segment)))

data SNil :: SListdata SNil

Instances

• RenderPath SNil (Text "")
• RenderPath (SCons n SNil) (QuoteLabel n)

Operator alias for Data.Undefined.NoProblem.SCons (right-associative / precedence 6)

class RenderPath :: SList -> Doc -> Constraintclass RenderPath (path :: SList) (render :: Doc) | path -> render

Instances

• RenderPath SNil (Text "")
• RenderPath (SCons n SNil) (QuoteLabel n)
• (RenderPath tail p) => RenderPath (SCons segment tail) (Beside p (Beside (Text ".") (QuoteLabel segment)))

class TypeMismatchErr :: Type -> Type -> SList -> Doc -> Constraintclass TypeMismatchErr (given :: Type) (expected :: Type) (path :: SList) (msg :: Doc) | path expected given -> msg

Instances

• (RenderPath p p') => TypeMismatchErr given expected p (Above (Beside (Text "Type mismatch on the path: { ") (Beside p' (Text " }. Expecting"))) (Above (Text "") (Above (Quote expected) (Above (Text "") (Above (Text "but got") (Above (Text "") (Above (Quote given) (Above (Text "") (Above (Text "If one of the types above is a type variable like `t2` or `r172`") (Above (Text "it probably means that you should provide type annotation to some") (Text "parts of your value (like `[] ∷ Array Int` or `Nothing ∷ Maybe String`)")))))))))))